<h1>Multi physics</h1>
<p>In this tutorial solving multiple problems on one geometric model. For this purpose <b>Beam model</b> will be used through which a passing electric current will generate heat and deform a model.</p>
<p>Such engineering problem will require to setup three problem types:</p>
<p>
<ol>
<li><b>Electrostatics</b> - Calculate electric current and produced heat.</li>
<li><b>Heat transfer</b> - Calculate temperature distribution.</li>
<li><b>Stress analysis</b> - Calculate thermal expansion (displacements) and resulting stress.</li>
</ol>
</p>
<h2>1. Load model</h2>
<p>Do the same as in the previous <b>Stress and deformation analysis</b> tutorial.</p>
<h2>2. Problem task flow</h2>
<p>The only difference to the process described in previous tutorial is to show how to create a <b>Problem task flow</b>. Everything else is done in the same way.</p>
<p style="background-color: #999999;"><b>Menu:</b> <i>Problem -> Problem(s) task flow</i></p>
<p>In <b>Problem type selector</b> select all three problem types and click <b>Ok</b>.</p>
<p><center><img src="image-Problem_type_selector-Multi.png"/><center></p>
<p>Your <b>Problem task flow</b> now should look like as on the following picture. If order is not the same or there are more entries, <b>Up</b>, <b>Down</b> and <b>Remove</b> buttons can be used to modify the flow.</p>
<p><center><img src="image-Problem_task_flow-Multi.png"/><center></p>
<h2>3. Assign material</h2>
<p>Do the same as in the previous <b>Stress and deformation analysis</b> tutorial.</p>
<h2>4. Assign boundary conditions</h2>
<p>Because there are multiple problem types selected multiple boundary conditions can be assigned to each entity. Assign boundary conditions as described in the following table.</p>
<p>
<table border="1">
<tr><th>Surface entity</th><th>Boundary conditions</th></tr>
<tr><td>Surface</td>
<td>
<dl><dt><u>Simple convection</u></dt><dd>Convection coefficient = 100 W/(m^2*K)</dd><dd>Temperature = 293.15 K</dd></dl>
</td>
</tr>
<tr><td>Load</td>
<td>
<dl>
<dt><u>Electric potential</u></dt><dd>Electric potential = 110 V</dd>
<dt><u>Simple convection</u></dt><dd>Convection coefficient = 100 W/(m^2*K)</dd><dd>Temperature = 293.15 K</dd>
</dl>
</td>
</tr>
<tr><td>Left</td>
<td rowspan="2">
<dl>
<dt><u>Displacement</u></dt><dd>Displacement in all directions = 0 m</dd>
<dt><u>Electric potential</u></dt><dd>Electric potential = -110 V</dd>
<dt><u>Simple convection</u></dt><dd>Convection coefficient = 100 W/(m^2*K)</dd><dd>Temperature = 293.15 K</dd>
</dl>
</td>
</tr>
<tr><td>Right</td></tr>
</table>
</p>
<h2>5. Assign environment conditions</h2>
<p>Assign following environment conditions to all model entities.</p>
<p>
<dl>
<dt><u>Gravitational acceleration</u></dt>
<dd>Gravitational acceleration in X direction = 0 m/s^2</dd>
<dd>Gravitational acceleration in Y direction = 0 m/s^2</dd>
<dd>Gravitational acceleration in Z direction = -9.80665 m/s^2</dd>
<dt><u>Temperature</u></dt><dd>Temperature = 293.15 K</dd>
</dl>
</p>
<h2>6. Solve problem</h2>
<p>Do the same as in the previous <b>Stress and deformation analysis</b> tutorial.</p>
<h2>7. Create a vector field</h2>
<p><b>Vector field</b> is an entity which will be used to visualize electric field.</p>
<p style="background-color: #999999;"><b>Menu:</b> <i>Geometry -> Vector field -> Create vector field</i></p>
<p>Select <b>volume</b> model entity and <b>Electric field</b> as shown on the picture below.</p>
<p><center><img src="image-Create_vector_field.png"/><center></p>
<p>Click <b>Ok</b> button to create the <b>Vector field</b>. Once created it will be added to the <b>Model tree</b> and results variables can be applied to it as to any other model entity.</p>
<h2>8. Apply results</h2>
<p>Do the same as in the previous <b>Stress and deformation analysis</b> tutorial. Additionally you can apply results to created <b>Vector field</b> entity.</p>
<p><center><img src="image-Applied_temperature_on_vector_field.png"/><center></p>
<p><center><img src="image-Applied_temperature_on_volume.png"/><center></p>
